[Amber] add opus-4.5 to the list of models available to ACP users.

[jeremyeder]

Issue Description

Verify that users have access to opus-4.5 through ACP. Create a skill that adds new models to this codebase and open a new issue with the proposed skill.

Files to Fix (optional)

No response

Fix Type

Code Formatting

Confirmation

• I understand this will create an automated PR
• The changes are low-risk and reversible
• All tests should continue to pass after fixes

[github-actions]

Amber Change Summary

The following files were modified:

 .../[name]/sessions/new/model-configuration.tsx    |  1 +
 .../src/components/create-session-dialog.tsx       |  1 +
 .../claude-code-runner/tests/test_model_mapping.py | 39 ++++++++++++++++------
 components/runners/claude-code-runner/wrapper.py   |  1 +
 4 files changed, 31 insertions(+), 11 deletions(-)

Next Steps:

• Review that changes match the issue description
• Verify no scope creep or unintended modifications
• A PR will be created shortly for formal review

[github-actions]

🤖 Amber has created a pull request to address this issue: #398

The changes are ready for review. All automated checks will run on the PR.